Summer in Queensland

[ozjohn]

Summer in Queensland. Although the article doesn't mention it the minimums over night  are not going below 25 deg. C and the humidity is over 80%.

Edited February 3, 2020 by ozjohn
More info

[Paddy]

If that's supposed to get my sympathy, I'll swap you!

North Devon this morning - 9C, fresh Breeze and drizzle...

 

[ozjohn]

Beautiful one dayday perfect the next is what they say about Queensland. Don't mention the cyclones and bushfires.

[alfnail]

3 hours ago, Paddy said:

If that's supposed to get my sympathy, I'll swap you!

North Devon this morning - 9C, fresh Breeze and drizzle...

 

Wouldn't that be snow if it was minus 9C Paddy? 😎

[Paddy]

39 minutes ago, alfnail said:

Wouldn't that be snow if it was minus 9C Paddy? 😎

Aha! It was meant to be a dash not a minus sign! Sorry for the confusion. (Though it feels as if it should be minus - Brrrr!)

 

[1949threepence]

Those high minimum overnight temperatures: 25 degrees - as standard. Without air con that would be unbearable if you weren't used to it. Although I suppose if you live in that kind of heat all the time, the body adapts and gets used to it.  

The record over night minimum in this country is about 24 degrees in early August 1990.  We haven't (yet) seen a 40 degrees by day, but I bet we will at some point fairly soon. 

In this country there'd be a medical emergency declared with those kind of temperatures, especially with the high humidity. 

I don't like extreme heat, but there are times I'd willingly swap to that for a day or two, given the procession of miserable, depressing dark wet days we have in the UK at this time of year. I know the light is improving a bit now, but it's always a slow process. Leaving for work in the dark, and returning home at "night" in the dark. In December it's dark before 4pm.    

[ozjohn]

Air conditioning is good but expensive to run. We run the air conditioning  in the day as we have roof top solar PV cells At night we have ceiling mounted fans which are good and cheap to run

I would like to have lithium batteries such as a Tesla Powerwall as a backup at night and cloudy days but they are very expensive  approx. $12000 and are not cost effective as they would not break even until after the warrantee period of 10 years had expired. Such is  the drawback with renewables they cannot deliver a reliable supply without some form of backup. I don't think anyone has thought too much about the disposal/recycling of lithium batteries which contain lithium which is a very reactive metal.

 

[AardHawk]

5 hours ago, ozjohn said:

Air conditioning is good but expensive to run. We run the air conditioning  in the day as we have roof top solar PV cells At night we have ceiling mounted fans which are good and cheap to run

You will be pleased to hear that nighttime PV panels (Anti-solar cells) are on the way https://www.sciencedaily.com/releases/2020/01/200129174512.htm

[ozjohn]

1 hour ago, AardHawk said:

You will be pleased to hear that nighttime PV panels (Anti-solar cells) are on the way https://www.sciencedaily.com/releases/2020/01/200129174512.htm

I looked at your reference and I am afraid I am sceptical .Conventional PV cells work by receiving a quanta of light energy which allows an electron to jump into the conduction band and become available as energy. Current PV cells have an efficiency of less than 25% with 30% the maximum which is set by quantum physics not engineering.  For a current 1m^2 PV cell normal to the sun would receive about 800 W. and output about 200 W.

In your anti PV cell reference it is suggesting that radiating from the cell to outer space energy can be generated. To start radiating energy to space this would represent a loss  in energy to the system and each quanta of light emitted would require electrons to lose energy binding them more tightly to their parent atom making them less likely to be in the conduction band. In quantum mechanics never say never but the probability would be low.

The reference does not attempt explain where the generated energy through the loss of energy comes from remembering that energy cannot be created or destroyed the fundamental  law of thermodynamics. It has to come from somewhere your reference vaguely suggests that the PV cell process is reversed and this energy from nowhere is available in the opposite direction  which is not convincing for the reasons given This one sounds like a perpetual motion machine.

Edited February 4, 2020 by ozjohn
typo

[ozjohn]

Redcliffe update. We've had a cool change today 26 degC max.  with rain. Tomorrow's forcast  22 to 25 degC with rain,  100mm. Sea temp. 27 degC.

Edited February 4, 2020 by ozjohn
More info.

[AardHawk]

13 hours ago, ozjohn said:

The reference does not attempt explain where the generated energy through the loss of energy comes from remembering that energy cannot be created or destroyed the fundamental  law of thermodynamics. It has to come from somewhere your reference vaguely suggests that the PV cell process is reversed and this energy from nowhere is available in the opposite direction  which is not convincing for the reasons given This one sounds like a perpetual motion machine.

I think they are suggesting it comes from the warm house (or perhaps from daytime solar heated water.)

[ozjohn]

4 hours ago, AardHawk said:

I think they are suggesting it comes from the warm house (or perhaps from daytime solar heated water.)

If that were the case they wouldn't be attempting to reverse the action of PV cells as suggested in the article. The PV cells would be operating in the conventional mode as if they were facing the sun ie they receive a quanta of IR from the warm house which energizes an electron to jump into the conduction band and available to produce a potential across the PN junction of the PV cell. A PV cell receiving IR radiation from a hot surface would certainly generate electricity providing the  doping of the semiconductor was consistent with the wavelength of the quanta of IR emitted from the warm house. but 50W/m^2 ? This very optimistic, also as the night cools so would the radiated power from the warm house reduce thus reducing the PV cells output further.

When I read the article it seem to imply that the PV cell was radiating to outer space which has a temperature of 4 deg K ( absolute zero 0 deg K or -273 deg C) which by some unexplained process released energy up to 50w/m^2 in the reverse direction to a conventional PV cell. For this to happen the energy has to come from somewhere or someone has found a way of getting round the laws of physics which is unlikely. If this were the case perpetual motion machines would become a reality coal, gas , oil and nuclear would be redundant.

Edited February 5, 2020 by ozjohn

[ozjohn]

.

. I appoligize  for my initial scepticism but I guess that's the engineer coming out never accept anything on face value. I have to say your post was the first I have heard of thermoradiative  cells and I have not seen anything so far from the renewable energy brigade in Australia. Thanks for alerting me.

It seems that these theromradiative cells are like  the QM equivalent of heat pump where a small amount of energy is expended by radiating it out to outer space and drawing a greater amount of energy from the environment which in turn gives electrons the energy to jump into the conduction band and become available as useable energy. I guess I was too tied up with the operation of conventional PV cells to see the difference. Thanks again for alerting me to this new technology. 

[AardHawk]

2 hours ago, ozjohn said:

.

. I appoligize  for my initial scepticism but I guess that's the engineer coming out never accept anything on face value. I have to say your post was the first I have heard of thermoradiative  cells and I have not seen anything so far from the renewable energy brigade in Australia. Thanks for alerting me.

It seems that these theromradiative cells are like  the QM equivalent of heat pump where a small amount of energy is expended by radiating it out to outer space and drawing a greater amount of energy from the environment which in turn gives electrons the energy to jump into the conduction band and become available as useable energy. I guess I was too tied up with the operation of conventional PV cells to see the difference. Thanks again for alerting me to this new technology. 

Apology accepted even though it was not required..

There were some other articles attached to that one giving some other details and ideas. Just how effective any of them would be, I dont know.

If heat is being sucked in from the surroundings, utilised, and then photons transmitted to outer space, then I think it would be good for cooling your house in Queensland, even if it didnt produce significant Kw. Not sure how it would get on in Canada though! 

[1949threepence]

On 2/3/2020 at 11:58 AM, ozjohn said:

Beautiful one dayday perfect the next is what they say about Queensland. Don't mention the cyclones and bushfires.

You've got a cyclone right now in Western Australia haven't you? 

[Fubar]

Dampier seems tro be the favoured landing place for these things.

I have a friend who has ships regularly in this area and he gets updates when one is in port or at anchor.

The map was from yesterday and shows expected position today (8th)

 

 

For some reason it insists on putting up two copies of the map. Apologies. 😣

Edited February 8, 2020 by Fubar

[ozjohn]

Fortunatly not many people live in the area. Cyclones on the east coast are a different matter.

[copper123]

Oz is welcome to all this rain we have had this year.......I am totally sick of it........September- feb rain rain rain

[Paddy]

2 hours ago, copper123 said:

Oz is welcome to all this rain we have had this year.......I am totally sick of it........September- feb rain rain rain

And I thought it was only happening in North Devon. Been in my new house for nearly a month now and barely explored the garden and outbuildings yet.

 

[copper123]

32 minutes ago, Paddy said:

And I thought it was only happening in North Devon. Been in my new house for nearly a month now and barely explored the garden and outbuildings yet.

 

Nicer place than the northwest , I am having similar probs here been in six months, at least the northwest is famous for its rain esp cumbria.

Thank god I managed to get our new shed up in the only month there was little rain august